Unfettered by caps on contributions or spending that apply to candidates, Indian tribes, labor unions, conservative Christians and Planned Parenthood have infused independent expenditure committees with $5 million and used $3.7 million of it in support of their preferred candidates and causes.

In a 48-hour period last week, labor unions and Indian tribes spent nearly $3 million on mailers, television spots and other efforts aimed at swaying the electorate. Almost all of it was spent on behalf of Democratic Lt. Gov. Cruz Bustamante and Republican state Sen. Tom McClintock, their favored candidates to replace Gov. Gray Davis if he is recalled. Many major donors to Bustamante and McClintock also double as independent operatives.

Conservative Christian Howard Ahmanson Jr., long a McClintock supporter, has spent $75,000 to set up a phone bank operation to urge voters to support McClintock. Environmentalists are preparing to spend several hundred thousand dollars advising voters to help Gov. Gray Davis retain his job.

Now that the federal courts have reinstated the Oct. 7 recall election date, other interests are expected to weigh in. Though they have not yet become a dominant part of the recall campaign, donors and consultants say the committees almost certainly will spend more than $10 million.

So far, the committees are helping candidates by amplifying their campaign themes. A television spot paid for by an Indian tribe on McClintock's behalf, for example, closely follows the ads that the McClintock campaign is airing. But as election day draws near, the independent committees could become political hit men.

In any campaign, these committees are the wild card. They are notable in the current campaign largely because this is the first time California has had a statewide race subject to contribution limits that apply to candidates themselves. Exactly which groups are planning independent campaigns, and what they're contemplating, is difficult to track. Dozens of committees have been formed in recent weeks; whether they receive cash won't be public record until after they start spending.

"With independent campaigns, it's difficult to follow the money," said Kim Alexander of the nonprofit California Voter Foundation, which promotes Internet disclosure of all campaign donations and expenditures.

The groups are proliferating, thanks to Proposition 34, the ballot measure that voters approved three years ago to restrict donations to political candidates. In campaign literature touting Proposition 34, promoters decried the fact that $100,000 gifts to candidates were common. But six- and even seven-figure checks continue to fly; they simply land in independent expenditure funds.

"You wouldn't see nearly as many of them but for the so-called reforms," said Fred Keeley, a Democrat who served three terms in the Assembly, and is contributing to an independent campaign aimed at encouraging environmentalists to vote to keep Davis as governor. "They're the existing big loophole in the law."

Some candidates denounce independent committees, largely because they can't -- at least, they're not supposed to -- have any control over them, and because their actions sometimes backfire.

In a legislative primary race last year, state employee unions trying to help a Republican candidate sent a mailer describing her foe as a religious conservative -- to conservatives. In Northern California, a police union "helped" a Republican state Senate candidate by sending a mailer to GOP voters urging that they not only elect the candidate but also support Democrats running for governor and other statewide offices.

In the recall contest, as independent players largely echo the campaign themes of Bustamante and McClintock, they're proving valuable to those candidates, who, unlike actor and GOP candidate Arnold Schwarzenegger, have no personal wealth and cannot fund their own campaigns.

Bustamante has raised $9 million for the current race. But that is only part of the cost of his campaign. Organized labor and Indian tribes rich with casino profits have poured $2.6 million more into independent committees in support of his candidacy.

And the Hotel Employees and Restaurant Employees International Union has embarked on what its California political director, Jack Gribbon, hopes will be a $2.5-million campaign to persuade 750,000 immigrants to vote against the recall and for Bustamante as a possible replacement for Davis.